From that embarrassing romp in North Vietnam to a stellar acting career to evangelical fitness guru, Jane Fonda has gone through more image makeovers than Madonna. Now, the ex-Mrs. Ted Turner has turned her considerable energies to Georgia's high teen-pregnancy rate. In 1995, Fonda founded the Georgia Campaign for Adolescent Pregnancy Prevention. She followed that up last October with a $1.3-million gift to Grady Hospital for a teen health clinic. And just this past summer, she gave $2 million to Emory University's School of Medicine for adolescent reproductive health research, training and program development. It could be helping; Georgia's rate of teen pregnancy has declined three years in a row. Best of all, she's still a plain Jane -- living in Poncey-Highlands and frequenting regular-joe joints like the Cabbagetown Grill.